The present invention relates, in general, to the field of signal transmitting and receiving rangefinding devices. More particularly, the present invention relates to a simplified, cost effective and efficient optical system and beam pathway design for laser-based distance measuring, or range-finding, devices.
Representative implementations of optical pathways for various optical instruments, including laser-based rangefinders, are described in, for example, U.S. Pat. No. 6,236,504 issuing May 22, 2001 for “Method and Device for Adjusting Eye Range by Means of Displacements of Prisms and Ocular Lenses”; U.S. Pat. No. 6,292,314 issuing Sep. 18, 2001 for “Prism System for Image Inversion in a Visual Observation Beam Path”; and U.S. Pat. No. 6,344,894 issuing Feb. 5, 2002 for: “Optical Axis Adjusting Structure for a Range Finder”. These comparatively complicated designs require the use of two or more relatively costly prisms along with as many as six or seven polished faces resulting in large, expensively implemented systems having little flexibility in the use of more than one type of in-sight display technologies.
While generally representative of the current state of the art in such designs, the afore-mentioned patents all describe systems of lenses and prisms which are relatively complex to implement, space inefficient, as well as costly to manufacture and assemble. Therefore, a need exists for a simplified, cost-effective and efficient optical system and beam pathway design which provides significant advantages over current conventional designs while nevertheless providing an accurate foundation for a compact, range-finding instrument having excellent beam transmission/reception and optical properties.